Mice immunized with plasmodial antigens demonstrated delayed-hypersensitivity to malarial antigens, a T cell function retreatment with Cyclophosphamide revealed increased DH activity and protection against lethal strains of Plasmodium berghei. Studies with nude mice suggest that T cells function in a helper cell capacity i.e. synthesis of protective antibody. BIBLIOGRAPHIC REFERENCES: Finerty, J.F. and Krehl, E.P.: Delayed immune reactions in mice immunized with malarial antigen. Am. J. Trop. Med. Hyg. 26: 377-381, 1977. Roberts, D.W., Rank, R.G., Weidanz, W.T. and Finerty, J.F.: Prevention of recrudesence in nude mice by thymic graft or hyperimmune serum. Inf. and Imm. 16: 821-826, 1977.